Date of Award

Spring 1983

Document Type

Dissertation

Degree Name

Doctor of Engineering Science in Chemical Engineering

Department

Chemical Engineering and Chemistry

First Advisor

David S. Kristol

Second Advisor

Richard Clyde Parker

Third Advisor

Angelo J. Perna

Fourth Advisor

Kenneth Sohn

Fifth Advisor

Carol A. Venanzi

Abstract

Acid hydrolysis of dextran and cellulose were studied with and without irradiation with ultrasonic waves of different frequencies (17 - 150 KHz), and powers (0.4 - 200 w/cm2). In the case of both materials, the hydrolysis reaction was found to be first order with respect to the activity of hydrogen ions in the reaction medium. Weight average molecular weight was evaluated at different durations of the reaction course. The reaction rate of dextran was found to be proportional to the weight average molecular weight raised to the power 4/3, and raised to the power 4 for cellulose.

The value of the activation energy was shown to be the same, either with or without ultrasound irradiation for both materials. It was found to be equal to 30,000 cal/mole for dextran, and 28,600 cal/mole for cellulose in a heterogeneous system.

A mathematical model for the rate constant under the effect of ultrasonic waves, temperature, and hydrogen ions activity, was proposed. This model then was used to predict the optimum enhancement, which was proved to be in agreement with experimental data.

Share

COinS